Effects of Wheat Malt Extract on Molecular and Behavioral Markers in Aged APP/PS1 and Wild-Type Mice

Growing evidence suggests an important pathogenetic role of brain-specific gangliosides in the mechanisms underlying Alzheimer's disease (AD), the most common form of dementia. Nutritional strategies targeting ganglioside sialylation-for example, through agglutinin-mediated modulation-have therefore attracted increasing research interest. In particular, wheat malt extract (WME), a food-derived source of wheat germ agglutinin (WGA) with high affinity for gangliosides, may influence molecular pathways involved in AD pathogenesis. Twelve-month-old female APPswe/PS1E9 transgenic mice, a model of AD, and wild-type (WT) littermates received WME or tap water for three weeks. Behavioral performance was subsequently assessed. Amyloid plaque burden and astrocyte activation were evaluated using Congo red staining and GFAP immunoreactivity, respectively. Gene expression of selected AD markers in the brain was quantified by RT-qPCR. Aged WT mice exhibited robust, region-specific molecular responses to WME, including upregulation of activity-dependent and synaptic plasticity genes (Arc, Egr1, Bdnf, Syp), enhancement of metabolic and insulin-related signaling (Pgc1a, Sirt1, Igf1r, Irs2), increased Cldn5 expression, and reduced pro-inflammatory Il1β expression. APP/PS1 mice exhibited limited response to WME, suggesting more persistent transcriptional signatures of synaptic impairment, metabolic dysregulation, and neuroinflammation than in WT mice. We found no significant effects of WME treatment on amyloid plaque density and behavior in APP/PS1 mice. No effects on astrocyte activation were observed in either group. These findings demonstrate that dietary WME counteracts abnormal behaviors and molecular changes in neuron plasticity, metabolic, and vascular markers under conditions of normal aging but fails to improve the hallmarks of AD pathology. This highlights the potential of WGA-containing nutrients as a preventive nutritional approach targeting pathogenic mechanisms of aging and, potentially, AD pathology.